Every summer, as eyes along the Gulf Coast and southeastern U.S. turn to the Atlantic Ocean for a months-long hurricane watch, Dr. Fred Semazzi looks farther east, to West Africa and the highlands of Ethiopia. There, the NC State professor of meteorology says, wave-like disturbances in the weather could provide clues as to how tropical storms subsequently form in the Atlantic.

As part of a five-year research project funded by the National Oceanic and Atmospheric Administration, Semazzi is using computer simulations to help forecasters better understand the genesis of hurricanes and improve climate prediction models. “There may be linkages back across the Indian Ocean,” he says. “Weather is global, and one small change on one side of the world could have widespread effects.”

Similarly, changes in the flow of the Nile River could impact East African politics. Semazzi is modeling the role of the regional climate on the Nile River Basin’s water resources. International treaties are based on diverting or sharing the Nile’s water, he says, and his simulations show the river’s total volume dropping over time. “This could further destabilize the area,” he says. Semazzi is very familiar with political instability, having grown up in Uganda during the reign of dictator Idi Amin. Escaping his homeland was the reason he became a meteorologist, he says. He had to choose an academic major that wasn’t offered in any college in Uganda

Given weather’s global nature, Semazzi and other meteorologists turn to high-performance computing to make predictions about year-to-year climate variability and change. Temperature, humidity, wind circulation, vegetation, and other variables are fed into algorithms, and millions of calculations are performed to show changes that will occur over a few days for short-term weather forecastsor many years for long-range climate projections. “We get solutions at many discrete points for as complete a picture as possible,” Semazzi says. “But we can never have a climate model forecast for every location over the entire world because of computer limitations and gaps in the observed climate data.”

Much of Semazzi’s work is funded by the U.S. Department of Commerce and the National Science Foundation, both interested in how climate affects industries from farming to tourism to utilities. For simulations that look at potential climate changes years from now, he also factors in human actions, such as deforestation or increased greenhouse gas emissions. “Long-range models are really more projections than predictions,” he says. “Some dire projections may never come to pass because society may respond with remedial actions.”